I don't see any need to make more of this requirement than the code already has. If the NEC doesn't specifically require something to be 'listed,' than it need not be listed, or even factory made.
Heck, someone could place a ground clamp on any old piece of rod or pipe, attach a length of #8, toss it in the leafcatcher and .. voila! .. the water is 'bonded.'
Just like, outside the pool, the 'equipotential grid' can be simple rebar, tied with ordinary tie wire.
What is critical is that these two be connected TO EACH OTHER. The whole purpose of the requirement is to ensure that there is no electrical potential between the pool water and the area just outside the shell. In the past this wasn't really a concern ... then we started making pools with either non-conductive or insulated shells.
Ironically, as the code wonks play lawyer, technology marches on. The typical 'pool' these days is very likely to be a vinyl sack with a 'rim' that floats, and a pump plugged into an extension cord from one of the general-use outdoor outlets. No filter, no grid, nothing ... heck, in the winter, they can set it up in their living room if they like. All you need is a garden hose.
Personally, I welcome ANY attempt to address possible concerns; the lack of a UL sticker isn't always a big deal.
